“As a head teacher I am staggered at the ages some parents let kids play the game at,” the father-of-three told the Essex Chronicle.

“We had an e-safety meeting with staff the very same day and it was made very clear to us children as young as six were using it. This is shocking and this comes out in these children’s writing, how they speak and how they behave with other children.

“All they want to do is play with guns and all they want to write about is guns and violence.”

The Boswells School headteacher David Crowe added: “It wouldn’t surprise if that was the motivation. They’d just project it onto the wall.”

The 18-certificate game was released to eager fans on September 17, and has received worldwide critical acclaim.